Optimization of pulsed electric field pre‐treatments to enhance health‐promoting glucosinolates in broccoli flowers and stalk

BACKGROUND The effect of pulsed electric field ( PEF ) treatment variables (electric field strength and treatment time) on the glucosinolate content of broccoli flowers and stalks was evaluated. Samples were subjected to electric field strengths from 1 to 4 kV cm −1 and treatment times from 50 to 1000 µs at 5 Hz. RESULTS Data fitted significantly ( P < 0.0014) the proposed second‐order response functions. The results showed that PEF combined treatment conditions of 4 kV cm −1 for 525 and 1000 µs were optimal to maximize glucosinolate levels in broccoli flowers (ranging from 187.1 to 212.5%) and stalks (ranging from 110.6 to 203.0%) respectively. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values, with low average mean deviations (E%) ranging from 0.59 to 8.80%. CONCLUSION The use of PEF processing at moderate conditions could be a suitable method to stimulate production of broccoli with high health‐promoting glucosinolate content. © 2014 Society of Chemical Industry